In many fields, it is desirable to have paint that appears as one color under a first light source and appears as a second color under a second light source. For example, star fields (such as those in planetariums and amusement park rides) ideally use a black background on which the star field can be projected. However, black backgrounds typically provide little to no screen gain, making projected star fields difficult to see. Screen gain measures the reflectivity of a screen or surface, normalized to a standard white (magnesium oxide) board. Screens with a screen gain of 1.0 have the same reflectivity as the standard, screens with a screen gain of less than 1.0 have lower reflectivity than the standard board, and screens with a screen gain of greater than 1.0 have a reflectivity that is greater than the standard board. Non-black backgrounds (such as grey) can be used in order to enhance the brightness of the projected stars by providing surfaces with higher screen gain than typical black backgrounds. However, non-black backgrounds may be perceptible to observers, thus destroying the illusion of a realistic star field with indeterminate depth.
Fluorescent paints have been used to create backgrounds of various colors. Many traditional fluorescent paints require a two-step application process. For example, a base coat having the desired base color is applied to a surface or substrate first. A second coat, comprising a colorless carrier material as well as the fluorescent pigment is then applied on top of the base coat. When the fluorescent pigment is not fluorescing, light merely passes through the colorless carrier material and is reflected outwardly by the base coat. When the fluorescent pigments are fluorescing, the light is absorbed by the fluorescent pigment within the colorless carrier material and then emitted outwardly through the colorless carrier material. Such two-step application processes are time consuming to apply when a relatively large area (e.g. thousands of square feet) must be painted.
Alternative methods of producing star fields include tiling display, such as LED screens, or routing fiber optic cable to holes in a black surface. However, the number of display screens required is typically cost prohibitive, and routing the fiber optic cable is highly labor intensive and results in a completely static star field, thus limiting the display options. Therefore, there is a need for an inexpensive way to provide a black background on which a bright, clear star field may be projected.